U.S. patent application number 14/919123 was filed with the patent office on 2016-02-11 for system and method of dpf passive enhancement through powertrain torque-speed management.
This patent application is currently assigned to CUMMINS INTELLECTUAL PROPERTY, INC.. The applicant listed for this patent is CUMMINS INTELLECTUAL PROPERTY, INC.. Invention is credited to Timothy R. FRAZIER, Vivek A. SUJAN.
Application Number | 20160040615 14/919123 |
Document ID | / |
Family ID | 46718058 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160040615 |
Kind Code |
A1 |
SUJAN; Vivek A. ; et
al. |
February 11, 2016 |
SYSTEM AND METHOD OF DPF PASSIVE ENHANCEMENT THROUGH POWERTRAIN
TORQUE-SPEED MANAGEMENT
Abstract
This disclosure provides a method and system for determining
recommendations for vehicle operation that reduce soot production
in view of a diesel particulate filter (DPF) of an exhaust
aftertreatment system. Recommendations generated can reduce
excessive particulate matter (PM) production during transient
engine events and provide for operating conditions favorable for
passive regeneration. In this way, less frequent active
regeneration of the DPF is needed and/or more opportunities are
provided for passive regeneration. The system and method can
utilize location and terrain information to anticipate and project
a window of operation in view of reducing soot production and soot
loading of the DPF, or provide the operator with instruction when
such opportunities are present or will soon be encountered.
Inventors: |
SUJAN; Vivek A.; (Columbus,
IN) ; FRAZIER; Timothy R.; (Columbus, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CUMMINS INTELLECTUAL PROPERTY, INC. |
Minneapolis |
MN |
US |
|
|
Assignee: |
CUMMINS INTELLECTUAL PROPERTY,
INC.
MINNEAPOLIS
MN
PACCAR, INC.
BELLEVUE
WA
EATON CORPORATION
CLEVELAND
OH
|
Family ID: |
46718058 |
Appl. No.: |
14/919123 |
Filed: |
October 21, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13407583 |
Feb 28, 2012 |
9194318 |
|
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14919123 |
|
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|
61447425 |
Feb 28, 2011 |
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Current U.S.
Class: |
701/108 |
Current CPC
Class: |
F01N 3/035 20130101;
F02D 2200/701 20130101; F02D 41/021 20130101; F01N 9/002 20130101;
F02D 41/029 20130101; F01N 3/0253 20130101; F01N 3/0232
20130101 |
International
Class: |
F02D 41/02 20060101
F02D041/02; F01N 9/00 20060101 F01N009/00; F01N 3/023 20060101
F01N003/023 |
Claims
1. A method to enhance the passive regeneration of a diesel
particulate filter performed by an engine system having a processor
and non-transitory computer-readable storage medium, the method
comprising: receiving, by the processor, current operating data
indicative of a vehicle current operating state based on at least
two of power demand, engine speed, engine torque, gear number, and
vehicle speed; receiving, by the processor, terrain data indicative
of terrain variation; determining, by the processor, a vehicle
target operating state based on engine exhaust particulate matter
and engine transients; and controlling, by the processor, engine
speed and transmission gear selection based on the vehicle target
operating state so as to reduce at least one of the engine exhaust
particulate matter and the engine transients.
2. The method of claim 1, wherein the terrain variation is based on
current vehicle location.
3. The method of claim 1, wherein the terrain variation is based on
upcoming vehicle location.
4. The method of claim 1, wherein reducing the engine transients is
determined on a per cylinder basis.
5. The method of claim 1, wherein the vehicle target operating
state is determined based on an estimated exhaust particulate
matter level present in the diesel particulate filter.
6. The method of claim 1, further comprising: estimating, by the
processor, a soot load relating to an amount of engine exhaust
particulate matter in the diesel particulate filter, wherein the
vehicle target operating state is determined based on the estimated
soot load.
7. The method of claim 1, further comprising: receiving, by the
processor, positioning related data; and determining, by the
processor, a position coordinate of a vehicle based on each of the
position coordinate and the terrain data.
8. A system adapted to enhance the passive regeneration of a diesel
particulate filter, comprising: an engine system; and a controller
operatively coupled to the engine system, the controller having a
processor and non-transitory computer-readable storage medium, the
controller including: a current operating state circuit including
current operating state data indicative of a vehicle current
operating state based on at least two of power demand, engine
speed, engine torque, gear number, and vehicle speed; a terrain
variation circuit including terrain data indicative of terrain
variation; a target operating state circuit structured to determine
a vehicle target operating state based on engine exhaust
particulate matter and engine transients; and an engine control
circuit structured to control engine speed based on the determined
vehicle target operating state so as to reduce the engine exhaust
particulate matter and the engine transients.
9. The system of claim 8, wherein the controller further includes a
transmission control circuit structured to control transmission
gear selection based on the determined vehicle target operating
state so as to reduce the engine exhaust particulate matter and the
engine transients.
10. The system of claim 8, wherein the controller further includes
a soot load estimate circuit structured to estimate an amount of
engine exhaust particulate matter in the diesel particulate filter,
wherein the target operating state circuit is structured to
determine the vehicle target operating state further based on the
estimate.
11. The system of claim 8, wherein the controller further includes
a position coordinate determining circuit structured to receive
data related to positioning and determine a vehicle position based
on each of the positioning data and the terrain data.
12. A method to enhance the passive regeneration of a diesel
particulate filter performed by an engine system having a processor
and non-transitory computer-readable storage medium, the method
comprising: receiving, by the processor, current operating data
indicative of a vehicle current operating state; determining, by
the processor, a vehicle target operating state based on the
vehicle current operating state so as to minimize fuel consumption
by each of the engine system and active regeneration anticipated to
be required by operation in the vehicle target operating state; and
providing, by the processor, an engine speed and transmission gear
shift recommendation based on the vehicle target operating
state.
13. The method of claim 12, wherein the current operating data
includes at least two of power demand, engine speed, engine torque,
gear number, and vehicle speed.
14. The method of claim 13, wherein the current operating data
further includes terrain data indicative of vehicle terrain.
15. The method of claim 12, wherein the fuel consumption is
determined based on an estimated power required for the vehicle
target operating state for at least one of a period of time, a
distance traveled, and an operation window.
16. The method of claim 15, wherein the fuel consumption is
determined further based on predicted future road conditions and at
least one of corresponding engine speed, torque, and fueling
requirements.
17. A system adapted to enhance the passive regeneration of a
diesel particulate filter, comprising: an engine system; and a
controller operatively coupled to the engine system, the controller
having a processor and non-transitory a computer-readable storage
medium, the controller including: a current operating state circuit
including current operating state data indicative of a vehicle
current operating state; a target operating state circuit
structured to determine a vehicle target operating state so as to
minimize fuel consumption by each of the engine system and active
regeneration anticipated to be required by operation in the vehicle
target operating state; and a recommendation circuit structured to
provide engine speed and transmission gear shift recommendations
based on the vehicle target operating state.
18. The system of claim 17, wherein the current operating data
includes at least two of power demand, engine speed, engine torque,
gear number, and vehicle speed.
19. The system of claim 17, wherein the controller further includes
a terrain variation circuit including terrain data indicative of
terrain variation, wherein the vehicle current operating state is
based at least in part on the terrain data.
20. The system of claim 17, wherein the fuel consumption is
determined based on an estimated power required for the vehicle
target operating state for at least one of a period of time, a
distance traveled, and an operation window.
21. The system of claim 20, wherein the fuel consumption is
determined further based on predicted future road conditions and at
least one of corresponding engine speed, torque, and fueling
requirements.
22. A method to enhance the passive regeneration of a diesel
particulate filter performed by an engine system having a processor
and non-transitory computer-readable storage medium, the method
comprising: receiving, by the processor, current operating data
indicative of a vehicle current operating state; determining, by
the processor, a vehicle target operating state based on the
vehicle current operating state so as to minimize fuel consumption
by each of the engine system and active regeneration anticipated to
be required by operation in the vehicle target operating state; and
controlling, by the processor, engine speed and transmission gear
selection based on the vehicle target operating state.
23. The method of claim 22, wherein the current operating data
includes at least two of power demand, engine speed, engine torque,
gear number, and vehicle speed.
24. The method of claim 23, wherein the current operating data
further includes terrain data indicative of vehicle terrain.
25. The method of claim 22, wherein the fuel consumption is
determined based on an estimated power required for the vehicle
target operating state for at least one of a period of time, a
distance traveled, and an operation window.
26. The method of claim 25, wherein the fuel consumption is
determined further based on predicted future road conditions and at
least one of corresponding engine speed, torque, and fueling
requirements.
27. A system adapted to enhance the passive regeneration of a
diesel particulate filter, comprising: an engine system; and a
controller operatively coupled to the engine system, the controller
having a processor and non-transitory a computer-readable storage
medium, the controller including: a current operating state circuit
including current operating state data indicative of a vehicle
current operating state; a target operating state circuit
structured to determine a vehicle target operating state so as to
minimize fuel consumption by each of the engine system and active
regeneration anticipated to be required by operation in the vehicle
target operating state; and an engine control circuit structured to
control engine speed based on the vehicle target operating
state.
28. The system of claim 27, wherein the controller further includes
a transmission control circuit structured to control transmission
gear selection based on the determined vehicle target operating
state.
29. The system of claim 27, wherein the current operating data
includes at least two of power demand, engine speed, engine torque,
gear number, and vehicle speed.
30. The system of claim 27, wherein the controller further includes
comprising a terrain variation circuit including terrain data
indicative of terrain variation, wherein the vehicle current
operating state is based at least in part on the terrain data.
31. The system of claim 27, wherein the fuel consumption is
determined based on an estimated power required for the vehicle
target operating state for at least one of a period of time, a
distance traveled, and an operation window.
32. The system of claim 27, wherein the fuel consumption is
determined further based on predicted future road conditions and at
least one of corresponding engine speed, torque, and fueling
requirements.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/407,583, filed on Feb. 28, 2012, which
claims the benefit of priority to Provisional Patent Application
No. 61/447,425 filed on Feb. 28, 2011, the entire contents of which
are hereby incorporated by reference.
TECHNICAL FIELD
[0002] This disclosure relates to improved aftertreatment
performance. More particularly, the present disclosure relates to
optimizing vehicle engine and transmission operations to improve
passive regeneration of the diesel particulate filter and reduce
engine exhaust particulate matter.
BACKGROUND
[0003] Governments have been imposing progressive mandates for
reducing amounts of particulate matter (PM) in exhaust emissions.
The diesel particulate matter filter (DPF) has been developed for
exhaust aftertreatment systems to remove diesel particulate matter
containing soot, unburned fuel, lubrication oil etc. from the
exhaust gas.
[0004] A DPF typically includes a filter encased in a canister that
is positioned in the diesel exhaust stream. The filter is designed
to collect PM while allowing exhaust gases to pass through it.
Types of DPFs include ceramic and silicon carbide materials, fiber
wound cartridges, knitted fiber silica coils, wire mesh and
sintered metals. DPFs have demonstrated reductions in PM by up to
90% or more, and can be used together with a DOC to reduce HC, CO,
and soluble organic fraction (SOF) of PM in diesel exhaust.
[0005] Because a DPF traps soot and other PM, it must be
regenerated from time-to-time because the volume of PM generated by
a diesel engine is sufficient to fill up and plug a DPF in a
relatively short time. The regeneration process burns off or
"oxidizes" PM that has accumulated in the filter. However, because
diesel exhaust temperatures often are not sufficiently high to burn
accumulated PM, various ways to raise the exhaust gas temperature
or to lower the oxidation temperature are utilized. Regeneration
can be accomplished passively by adding a catalyst to the filter.
For example, a diesel oxidation catalyst (DOC) can be provided
upstream of a DPF to oxidize NO to generate NO.sub.2 (requiring
accurate control to maintain the mass ratio of NO/PM in engine-out
exhaust gas), which in turn oxidizes the PM in the downstream DPF.
Alternatively, regeneration can be achieved actively by increasing
the exhaust temperature through a variety of approaches, a fuel
burner, resistive heating coils or late fuel injection.
[0006] However, running active DPF regeneration cycles involve
injecting energy into the engine system and result in excess fuel
use, and thus excess cost. Further, managing the soot load in the
DPF in lean burning engine systems to reduce active cycling is
difficult because operation of the engine system frequently
involves soot producing transients. For instance, transients
involving throttling increase fuel amounts in the air to fuel
mixture such that the ratio can approach or exceed stoichiometric
levels, resulting in excessive PM trapped by the DPF, and
consequently requiring more active regeneration cycles.
SUMMARY
[0007] This disclosure provides a method and system for determining
recommendations for powertrain operation that reduce soot
production in connection with managing a diesel particulate filter
(DPF) of an exhaust aftertreatment system. Recommendations
generated reduce excessive particulate matter (PM) production
during transient engine events and can provide operating conditions
favorable for passive regeneration. In this way, less frequent
active regeneration of the DPF is needed and/or more opportunities
are provided for passive regeneration.
[0008] In one aspect of the disclosure, a method to enhance the
passive regeneration of a DPF includes receiving current operating
data indicative of a vehicle current operating state based on at
least two of power demand, engine speed, engine torque, gear
number, and vehicle speed; receiving terrain data indicative of
terrain variation; determining a vehicle target operating state
based on engine exhaust PM and engine transients; and providing an
engine speed and transmission gear shift recommendation based on
the vehicle target operating state to reduce at least one of the
engine exhaust PM and the engine transients.
[0009] In another aspect of the disclosure, a system adapted to
enhance the passive regeneration of a DPF includes a current
operating state module including current operating state data
indicative of a vehicle current operating state based on at least
two of power demand, engine speed, engine torque, gear number, and
vehicle speed; a terrain variation module including terrain data
indicative of terrain variation; a target operating state module
containing a vehicle target operating state based on engine exhaust
PM and engine transients; and a recommendation module containing
engine speed and transmission gear shift recommendations to reduce
the engine exhaust PM and the engine transients.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a diagram of an exhaust aftertreatment system
fluidly coupled downstream of an energy conversion device.
[0011] FIG. 2 is a diagram of an engine system according to an
exemplary embodiment.
[0012] FIG. 3 is a diagram showing more details of control related
modules present in exemplary engine system shown in FIG. 2.
[0013] FIG. 4 is a diagram showing an example of a cycle efficiency
management module along with exemplary inputs and generated
outputs.
[0014] FIG. 5 is a process flow diagram of a method for enhancing
passive regeneration of a DPF according to an exemplary
embodiment.
DETAILED DESCRIPTION
[0015] FIG. 1 shows an exemplary exhaust aftertreatment system 1
fluidly coupled downstream of an energy conversion device 2, such
as a turbine of a turbocharger. The exhaust aftertreatmnent system
1 includes a DOC 3 in the exhaust gas path downstream of the energy
conversion device 2, a diesel particulate filter (DPI') 4 in the
exhaust gas path downstream of the DOC 3. The elements of the
energy conversion device 2 and the aftertreatment system 1 are
fluidly connected via exhaust gas conduit sections 6a-6d.
Additional elements can be included in the aftertreatment system I,
such as an SCR (not shown) positioned downstream of the DOC 3 and
DPF 4. A hydrocarbon (1-IC) doser 5 is provided in the exhaust gas
conduit segment 6b between the energy conversion device 2 and the
DOC 3 to inject fuel into the exhaust gas flow, for example, during
an active regeneration cycle of the DPF 4. The soot load in the DPF
4 can be monitored using a delta-P soot load estimator (SLE), in
which soot load estimation is determined based on pressure sensors
measurement across the DPF. 4, or using a model-based SLE.
[0016] Due to the high cost of active regeneration of the DPF 4,
opportunities to either enhance the passive regeneration
capabilities or reduce the amount of exhaust particulate matter
(PM) from the engine are of significant value. Further,
opportunities to perform complete active regenerations are limited,
which further increases the need for increased passive regeneration
as well as the reduction of engine exhaust PM. The challenge is to
optimally run an engine so as to maximize the passive regeneration
of a DPF by managing both engine speed and engine transients
through powertrain/driveline control, and in the longer run, use
the strategy that is most efficient. For instance, a condition may
exist in which less efficient operation of the engine (e.g.,
downshifting to a lower numbered gear to increase engine speed) is
more economical because the additional fuel consumed by changing
the operating state (i.e., downshifting) may be less than fuel
consumed by a regeneration cycle of the DPF 4 otherwise required
based on the SLE output if the current operating state is
maintained. Thus, optimization of powertrain torque-speed
management can include projecting required power for the vehicle
operation over a period of time, a distance traveled, or operation
window, and determining an optimal operating mode with
consideration to fuel consumed by the operating mode and any
required regeneration. This is especially useful in engine systems
having access to positioning and terrain data, for example, using
GPS and terrain/routing map data, and operation in cruise control
mode, where required power in a the projected operating window can
be readily and accurately estimated.
[0017] To optimize vehicle engine and transmission operations to
improve passive regeneration of the DPF, applicants introduce a
Cycle Efficiency Management (CEM) module. The CEM module employs
control processes to furnish an operator with anticipated and
currently desired vehicle operational behavior to optimize fuel
economy. The CEM control processes focus on powertrain components
such as engine, transmission, exhaust aftertreatment devices,
accessories, final drive, wheels and vehicle. The processes can
interface with the operator to provide guidance as to appropriate
vehicle speed/power targets and transmission gear selection
targets. The CEM module is useful in conditioning an operator to
optimize behavior based on certain performance criteria.
[0018] FIG. 2 shows a diagram of an exemplary engine system 10,
which can be integrated into a vehicle (not shown), such as a truck
or an automobile. Engine system 10 includes a powertrain system 20
including an internal combustion engine 30 and a transmission 40 of
either a CVT or a discrete geared type. Also included in engine
system 10 are the exhaust aftertreatment system 1 (including DPF
4), an engine control module (ECM) 60, a CEM module 70, and a
transmission control unit (TCU) module 80. The components of engine
system 10 communicate with ECM 60 and one another via a network
system 100, which can be, for example, a controller area network
(CAN). The engine system 10 can include a number of additional
components not shown in FIG. 2.
[0019] FIG. 3 shows more details of control related modules that
can be present in exemplary network system 100 of the engine system
10. Network system 100 includes the ECM 60, CEM module 70, and TCU
module 80 shown in FIG. 1, and additional modules that communicate
with ECM 60, CEM module 7, and/or TCU module 8 via network 10
(e.g., a CAN). It is to be appreciated that while modules in FIG. 3
are shown as separate, but communicatively coupled modules, all or
some of these depicted modules can be grouped in any appropriate
manner and/or combined to form one or more modules. For example,
all depicted modules can be included with the ECM 60.
[0020] As shown in FIG. 3, the additional modules include an engine
parameter/operating conditions module 120 configured to receive
predetermined vehicle parameters and current vehicle operating
conditions, a road terrain and routing module 130 configured to
receive and/or store terrain profile data/information and routing
information (destination/multi-destination routing), and an
operator interface module 140 configured to receive operator input
or other sourced input, and provide output from the CEM 70 to the
operator. Any of the depicted modules can be configured to
communicate with one another via communications module 150 (e.g., a
CAN network module). A DPF management module 160 of the CEM module
70 determines a target operating state based on engine exhaust PM
and engine transients. DPF management module 160 communicates with
ECM 60 and TCU 80 to provide recommended operation that optimizes
(typically minimizes) engine out PM through limiting engine
transients.
[0021] Communications module 150 can include a GPS unit 152 to
receive position data to determine coordinate positioning, and/or
to supply data in advance of an operation or forthcoming positions
or in real-time as the vehicle is operated and route traversed.
Embodiments can provide for road terrain data to be maintained in
computer storage and downloaded to CEM module 70 prior to the start
of a trip or transmitted wirelessly over-the-air at any time, for
example, by using cellular technology. The positioning information
provided by GPS unit 152 can be used by operator interface module
140 and/or the road terrain and routing module 130 to determine
where the vehicle is on a route, the current road conditions, and
to predict future road conditions and related engine speed and
fueling/torque requirements.
[0022] CEM module 70 can receive information from ECM 60, engine
parameter/operating conditions module 120, the road terrain module
130, and/or the operator interface module 140 via communications
module 150. The CEM 70 can include or have access to a data from a
soot emission model (not shown) that can estimate an amount of soot
that would be produced for a particular engine speed and torque.
The soot emission model can be included, for example, in the ECM
60. This information can be used by DPF management module 160 to
determine whether to recommend to ECM 60 an operating state that
optimizes passive regeneration or minimizes soot production while
still providing the required power. Further, the recommendation may
consider other data, such as routing, projected time of delivery,
and/or weather conditions, when determining an operation state to
recommend. In an exemplary embodiment, engine transients are
minimized by operating the engine in a range, or window of low
speeds. Data such as routing, point of departure, destination,
allowable travel time etc. can be provided by the operator via the
operator interface module (e.g., via a touch screen, display,
microphone or other interface device) or communicated to road
terrain routing module 130 via communications module 150, for
example.
[0023] FIG. 4 shows a more detailed example of a CEM module 70
along with exemplary inputs and generated outputs. The inputs can
include power demand, engine speed, engine temperature, engine
torque, gear number (transmission type), vehicle speed fueling maps
(hot and cold) and terrain/positioning information. CEM module 70
determines a recommendation, for example, containing engine speed
and transmission gear shift recommendations to ECM 60 and TCU 80
that optimizes (typically minimizes) engine exhaust PM by limiting
engine transients. This can be achieved with the aid of data
available from GPS device 152, and/or an SLE module 165, which
monitors and estimates soot loading (PM) in the DPF 4. The SLE
module 165 can be provided elsewhere in network system 100, for
example, in ECM 60, and communicate with DPF module 160 via network
system 100. In this embodiment, data from GPS unit 152 indicating
vehicle positioning and upcoming terrain variation is supplied to
CEM module 70, which then can evaluate the terrain variation, the
position of the vehicle in the terrain, and anticipates the engine
load under various options and combinations of options.
[0024] For example, one option that can be considered by DPF
management module 160 is translating all immediate upcoming terrain
variation directly to engine load using the current transmission
gear position, that is, without changing the gear state of the
transmission 40.
[0025] Another option DPF management module 160 can consider
includes considering engine load transients based on a +1/-1 (or
similar) gear shift from the current transmission state or engine
load transients with cylinder cutout. That is, the effects of an
upshift to one or more higher transmission gears or downshift to
one or more lower transmission gears can be considered for reducing
transients of an upcoming event, or to change a current operating
state to a more optimal state (e.g., lower speed) in view of DPF
management.
[0026] Options for consideration by the DPF management module 160
include considerations made to place the engine 30 in a more
oxygen-fuel concentration (OFC) conservative state in preparation
for an upcoming transient, such as an increased load, and
considerations made to place the future state of the engine 30 to
reduce the transient from the current state (on a per cylinder
basis).
[0027] The forgoing options and others, as well as their
combinations, can be used to identify optimal engine-transmission
relationships as a function of terrain variation. In an embodiment,
these options can be considered with the state of soot loading in
the DPF 4, for example, as estimated by the SLE module 165. For
example, an amount of allowable soot production during a window of
operation can be based in part on the amount of soot present in the
DPF. Hence, when considering the available operating options, the
allowable margins can change with estimated PM.
[0028] In addition to limiting engine transients to mitigate the
generation of engine PM, the engine 30 and transmission 40 may also
be managed to operate the engine 30 at lower speeds. By operating
the engine 30 at lower speeds, passive regeneration opportunities
continue to be available for the aftertreatment system to
regenerate DPF 4. By shifting the transmission appropriately, the
engine may be slowed down (or maintained in a specific speed
window) based on current and future expected loads based on the
terrain profile.
[0029] Additionally, the engine system 10 can maintain a balance
between the engine 30 operating closer to its peak brake specific
fuel consumption (BSFC), which may be achieved at a given engine
speed by also cutting out cylinders as appropriate (i.e., cutting
fuel, or fuel and air to one or more cylinders such that the
remaining cylinders are operating closer to peak BSFC); the exhaust
flow rate/temperature; and the ability to provide the desired
transient response (such as sudden acceleration) in near future
time events.
[0030] The engine speed also can be maintained at an overall lower
value by shifting the engine governed-speed curve based on the need
for more aggressive passive regeneration opportunities. Exemplary
embodiments provide a benefit of increased freight efficiency in
transporting cargo from source to destination. Inputs to process
can also include engine fueling maps and engine braking/friction
maps. Additional benefits include reduction of failed active DPF
regeneration attempts and improvement in product life/warranty.
[0031] Both approaches--limiting engine transients and reducing
engine speed--make use of an engine-transmission integrated system,
where data in the form of GPS information can be used to supplement
the decision making process to consider current and future terrain
information. Without the GPS signal, optimal decisions would, in
part, be based on the current engine state, throttle command,
aftertreatment state and the transmission state. Although not all
benefits would be realized, the non-GPS process could still
coordinate activities with the transmission to minimize transients
and maintain the engine at a relatively low overall operating
speed.
[0032] In an exemplary embodiment, CEM module 70 performs
supervisory DPF management of the engine system 10. In an exemplary
embodiment, CEM module 70 can determine whether operator-controlled
changes in engine speed and torque, for example, by down-shifting,
no-shifting or up-shifting the transmission from its current gear
and/or throttle adjustment to a condition favorable for reducing
soot production or enhancing passive regeneration. By down-shifting
the transmission upon entering an upgrade, for example, the engine
can operate at a higher speed while producing the same amount of
driveshaft power as with operation at lower speed, and can avoid
the excess soot production that would otherwise be produces with
increased throttling (fueling) at a lower engine speed. Thus, by
generating recommendations for shifting the transmission up or down
and/or increasing or decreasing the fueling rate via throttling
adjustment, CEM module 70 can offer instruction to the operator
during opportunities where more optimal engine out PM operation is
possible. Generated recommendations can be indicated to the
operator via a visible or audible interface (e.g., display,
speaker, etc.).
[0033] Additionally, CEM module 70 can generate cost/economy
benefit information for historical storage and/or display, for
example, via operator interface module 140. This information can be
provided as an instantaneous value, as a function development over
a window (e.g., a look-ahead window), over an entire trip (source
to destination), or to show benefit, cost savings, or performance
of any other definable cumulative period.
[0034] FIG. 5 is a process flow diagram of an exemplary method 200
that enhances passive regeneration of a DPF. Starting in process
210, the method includes receiving data indicative of vehicle
current operating state based on factors including, for example,
power demand, engine speed and torque, gear number and vehicle
speed. In process 220, data indicative of terrain variation is
received. Next, in process 230, a vehicle target operating state is
determined based on engine exhaust PM and engine transients.
Process 240 provides an engine speed and transmission gear shift
recommendation in view of reducing the engine exhaust PM and engine
transients. The method can be restarted, for example, for another
window of time or distance, when another transient condition is
detected, as directed by the operator, or run continuously. Terrain
variation can be based on current vehicle location or upcoming
vehicle location.
[0035] Exemplary embodiments provide a system adapted to enhance
the passive regeneration of a DPF. The system comprises a current
operating state module including data indicative of vehicle current
operating state based on at least two of power demand, engine
speed, engine torque, gear number, and vehicle speed. The system
further comprises terrain variation module including data
indicative of terrain variation, a target operating state module
containing a vehicle target operating state based on engine exhaust
PM and engine transients, and a recommendation module containing
engine speed and transmission gear shift recommendations in view of
reducing said engine exhaust PM and engine transients.
[0036] Exemplary embodiments provide a system and method for
optimizing vehicle engine and transmission operations to improve
passive regeneration of the DPF and reduce engine exhaust PM to be
implemented in computer programmable software and stored in
tangible computer readable media. Such an embodiment would comprise
a computer readable storage medium encoded with computer executable
instructions, which when executed by a processor, perform the
method for maximizing the passive regeneration of a DPF, as
disclosed above.
[0037] Many aspects of this disclosure are described in terms of
logic units or modules that include sequences of actions to be
performed by elements of a control module and/or a network system,
which can be a computer system or other hardware capable of
executing programmed instructions. These elements can be embodied
in a controller of an engine system, such as ECM 60, multiple
controllers, or in a controller separate from, and communicating
with the ECM 60 or distributed across several modules. In an
embodiment, the ECM 60, CEM 70, and other depicted and described
modules can be part of a CAN in which the controller, sensor,
actuators communicate via digital CAN messages. It will be
recognized that in embodiments consistent with the present
disclosure, each of the various actions could be performed by
specialized circuits (e.g., discrete logic gates interconnected to
perform a specialized function), by program instructions, such as
program modules, being executed by one or more processors (e.g., a
central processing unit (CPU) or microprocessor), or by a
combination of both, all of which can be implemented in a hardware
and/or software of the ECM 60 and/or other controller, plural
controllers, and/or modules, each of which can utilize a processor
or share a processor with another unit (module, controller etc.) to
perform actions required. For example, the engine
parameter/operating conditions module 120 can be implemented as
separate modules for the engine parameters and current operating
conditions, and each module can be part of the ECM 60 or as a
separately provided module. Logic of embodiments consistent with
the disclosure can be implemented with any type of appropriate
hardware and/or software, with portions residing in the form of
computer readable storage medium with a control algorithm recorded
thereon such as the executable logic and instructions disclosed
herein, and can be programmed, for example, to include one or more
singular or multi-dimensional engine and turbine look-up tables
and/or calibration parameters. The computer readable medium
comprise tangible forms of media, for example, a random access
memory (RAM), a read-only memory (ROM), an erasable programmable
read-only memory (e.g., EPROM, EEPROM, or Flash memory), an optical
fiber, and a portable compact disc read-only memory (CD-ROM), or
any other solid-state, magnetic, and/or optical disk medium capable
of storing information. Thus, various aspects can be embodied in
many different forms, and all such forms are contemplated to be
consistent with this disclosure.
[0038] While various embodiments in accordance with the present
disclosure have been shown and described herein, it is understood
that the present disclosure is not limited these embodiments. Those
skilled in the art will appreciate that other embodiments according
to the present disclosure may include changes, modifications and
further applications from embodiments described herein.
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